'Outnumbered': Stories Of Civil War BattlesHow did 6,000 British soldiers commanded by Henry the Fifth topple 30,000 Frenchmen? What about the Civil War's Battle of Chancellorsville, where Robert E. Lee's Confederate force was outmanned by more than 2-to-1, yet rallied to win? Author Cormac O'Brien shares the answers with host Guy Raz. They're among the 14 battles he explores in his book Outnumbered: Incredible Stories of History's Most Surprising Battlefield Upsets.

How did 6,000 British soldiers commanded by Henry the Fifth topple 30,000 Frenchmen? What about the Civil War's Battle of Chancellorsville, where Robert E. Lee's Confederate force was outmanned by more than 2-to-1, yet rallied to win? Author Cormac O'Brien shares the answers with host Guy Raz. They're among the 14 battles he explores in his book Outnumbered: Incredible Stories of History's Most Surprising Battlefield Upsets.

GUY RAZ, host:

Now, one of the defining moments of that war came in the spring of 1863. President Lincoln had just appointed a young general, Joseph Hooker, to command the Union forces of the Army of the Potomac, and Hooker would face his first big test against the famed Confederate General Robert E. Lee near a farm in Chancellorsville, Virginia.

Hooker had around 133,000 Union troops at his disposal. Lee had just 60,000. Yet, it was Lee who won that battle against unbelievable odds.

It's a fight that's chronicled in a new book about the most amazing battlefield upsets in history. It's called "Outnumbered," and the author Cormac O'Brien joins me from New York.

RAZ: Okay so Chancellorsville, it's this amazingly legendary battle not only because of the odds but because of the men who were involved. We've got Robert E. Lee and Stonewall Jackson and Jeb Stuart and Joseph Hooker. Was it a case of Robert E. Lee simply sort of being a better military commander than the Union general Joseph Hooker?

Mr. O'BRIEN: I believe so. Going into the battle, Hooker had everything going for him. It's one of the best plans any Union general had come up with this far into the war, and it got off to a sensational start.

RAZ: He was going to cross the Rappahannock River.

Mr. O'BRIEN: In crossing the Rappahannock, he planned, Hooker planned, on putting himself basically on the far left flank of Lee's army, and he succeeded in doing that. He got across the river. And it's then that things started going a little awry for him.

RAZ: How much did luck end up playing a role because as you say, I mean, almost everything that could go wrong for General Hooker did go wrong. I mean, the German troops rebelled. He lost communications with one of his top commanders, John Sedgwick. So was part of this luck, or was a lot of this the fact that Robert E. Lee was just a great general?

Mr. O'BRIEN: Some of it was luck. You're right. You bring up some good points. But I think Chancellorsville is definitely a case where the South out-generaled the north.

RAZ: All right, Cormac O'Brien, I should mention that your book looks at 14 battles stretching all the way back to Salamis in 480 B.C., but I want to ask about a more recent battle first, Agincourt. It takes place on a single day in northern France, October 25, 1415, 6,000 English soldiers under the command of Henry VI defeat as many as 30,000 French troops. How was that possible?

Mr. O'BRIEN: One of the advantages Henry had going for his Englishmen was that they were a cohesive unit. Only a thousand of them were armored men at arms or knights, and the other 5,000 were longbowmen. This is definitely a case where weaponry comes very much to the fore.

The French, by contrast, they had a great deal of leadership but no direction.

RAZ: And they just could not out compete with the technology that the English under Henry V had.

Mr. O'BRIEN: Exactly. He placed his longbowmen on the flanks. Each archer had a stake that he drove into the ground before him, creating a kind of hedgehog of wooden stakes to defend themselves against oncoming cavalry. And in the middle were Henry and his men at arms, who received the attack of the French coming on after being savaged on the flanks by the archers.

RAZ: Okay, we have time for one more upset battle, the Battle of Alesia, Cormac O'Brien. This is Julius Caesar's defining battle before he would eventually go back to Italy, cross the Rubicon and then create basically a dictatorship in Rome.

That battle in Alesia happens in September of 52 B.C. Caesar has 50,000 Romans, and he faces 200,000 Gauls, and he wins.

Mr. O'BRIEN: This is a classic example of the Roman way of war. He basically surrounds Vercingetorix and his...

RAZ: Who is the commander of the Gauls.

Mr. O'BRIEN: Exactly. Basically, Caesar sets up a ring of fortifications 11 miles long, a circuit entirely surrounding the plateau, intended to starve the defenders out.

RAZ: And this, of course, seals Caesar's fate as a legendary military commander. France or Gaul becomes a Roman province from that point forward.

Mr. O'BRIEN: Yes, the people looked at him as a kind of demigod at this point, and he's able to leverage this into a dictatorship after coming home.

RAZ: Cormac O'Brien, in all the battles you looked at, from Salamis to Narva to Singapore in 1942, what did you find that they all had in common?

Mr. O'BRIEN: First and foremost, cooler heads always prevail, and they think their way out. They don't act rashly. They do act often very assertively. There's also on the other side almost invariably a great deal of overconfidence, which kills an army again and again and again.

RAZ: That's Cormac O'Brien. He's the author of the new book "Outnumbered: Incredible Stories of History's Most Surprising Battlefield Upsets."

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